/*
 * Copyright (C) 2021 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.sentry.config;

import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

/**
 * Wrapper around multiple {@link PropertiesProvider}. It tries to resolve property from the first
 * provider to the last. Returns {@code null} if property has not been found in any of the
 * configured providers.
 *
 * @since 2021-06-02
 */
final class CompositePropertiesProvider implements PropertiesProvider {
    private final @NotNull List<PropertiesProvider> providers;

    /**
     * constructor
     *
     * @param providers providersList
     */
    public CompositePropertiesProvider(@NotNull List<PropertiesProvider> providers) {
        this.providers = providers;
    }

    @Override
    public @Nullable String getProperty(@NotNull String property) {
        for (final PropertiesProvider provider : providers) {
            final String result = provider.getProperty(property);
            if (result != null) {
                return result;
            }
        }
        return null;
    }

    @Override
    public @NotNull Map<String, String> getMap(final @NotNull String property) {
        for (final PropertiesProvider provider : providers) {
            final Map<String, String> result = provider.getMap(property);
            if (!result.isEmpty()) {
                return result;
            }
        }
        return new ConcurrentHashMap<>();
    }
}
